Lab - Keytag Maker

• Partss A, B, C, and D - These four parts are complimentary, and each week there will be four groups that will rotate through all four labs.

• Group Size: 3 students, 4 rotating stations

• These laboratories will be used to pull together 4 individual control systems into a complete manufacturing control system. Although each group will solve a different control problem, each laboratory will end with all stations in a fully functioning control system.

• These four labs will all use an Allen-Bradley PLC-5 to control the stations.

• The descriptions below will be used to develop a design and ladder logic before arriving at the laboratory. All laboratories are to be done on design sheets like those found in the course notes, or equivalent.

• The basic schedule for the first lab is shown below for the first and second weeks.

• NOTE: In this lab three of the stations use the hole detect to start an operation. Even when the operation is done the hole in the keytag will remain. You must write your program so that after the press has retracted the process will not start immediately. Only after the hole is gone will the program start looking for a new hole. You might want to add another state that waits until the hole is gone.

3.2.1 Part A - Shear Press

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Objective:

A PLC will be used for control of a hydraulic cylinder that will shear off keytags.

Pre-Lab:

1. Examine the other components in the lab and determine what is required for proper operation of the shear.

2. Design the controls for the press.

3. Develop the ladder logic required for operation

Process Description:

The shear press will detect when the material is in place for shearing when a hole is detected by an optical sensor mounted. When sensed it will set a bit true in memory (B3:0/0) that will cause the material feeder to stop. A pneumatic cylinder will be actuated to clamp the strip. At this point shearing will begin by advancing the hydraulic cylinder until a hydraulic cylinder advanced limit switch is actuated. At this point the advance solenoid will be turned off, and the return cylinder solenoid will be actuated. This will continue until the retracted limit switch is actuated. At this point both the hydraulic solenoids are turned off. Finally the pneumatic solenoid is released, and the material feeder is allowed to continue.

PLC Outputs:

An AC Output card to output 120Vac.

- shear retract solenoid

- shear advance solenoid

- pneumatic solenoid to clamp material

PLC Inputs:

An AC Input card to accept 120Vac.

- hydraulic cylinder retracted limit switch

- hydraulic cylinder advanced limit switch

- control power on

- auto mode selected

- hydraulic power on

Procedure:

1. Make the electrical connections between the PLC and the shear station.

2. Enter the Ladder logic, and test the module by itself.

3. Integrate the components with the other parts of the system and produce parts.

Submission:

1. Pre-lab and updated laboratory materials.

3.2.2 Part B - Feeder Positioning

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Objective: a PLC will be used to position a material transport system driven by a motor.

Pre-Lab:

1. Examine the other components in the labs and determine what is required for proper operation of the feeder.

2. Design the controls for the material feeder.

2. Develop the ladder logic required for operation

Process Description:

The feeder uses a motor to advance the material strip. The feeder will continue to advance the material until the drill press orders the feeding to stop by setting flags true.

PLC Outputs:

A relay output card

PLC Inputs:

An AC Input card

- control power on (master power for the station)

- automatic mode on (must be on for PLC control)

Procedure:

1. Make the electrical connections between the PLC and the feeder station.

2. Enter the Ladder logic, and test the module by itself.

3. Integrate the components with the other parts of the system and produce parts.

Submission:

1. Pre-lab and updated laboratory materials.

3.2.3 Part C - Stamping Press Control

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Objective: a PLC will be used to control an stamping press.

Pre-Lab:

1. Examine the other components in the lab and determine what is required for proper operation of the press.

2. Design the controls for the press.

2. Develop the ladder logic required for operation

Process Description:

The stamping press will detect when the material is in place for stamping (embossing) when a hole is detected by an optical sensor mounted. When sensed it will set a bit true in memory (B3:0/01) that will cause the material feeder to stop. A pneumatic cylinder will be actuated to clamp the strip. At this point stamping will begin by advancing the hydraulic cylinder until a hydraulic cylinder advanced limit switch is actuated. At this point the advance solenoid will be turned off, a two (or more) delay (0.5s) is required to allow the embossing to occur. After this the return cylinder solenoid will be actuated. This will continue until the retracted limit switch is actuated. At this point both the hydraulic solenoids are turned off. The pneumatic solenoid is released, and the material feeder is allowed to continue.

PLC Inputs:

An AC Input card to accept 120Vac.

- hydraulic cylinder retracted limit switch

- hydraulic cylinder advanced limit switch

- control power on (master power for the station)

- auto mode selected (must be on for plc operation)

- hydraulic power on

PLC Outputs:

An AC Output card to output 120Vac.

- press retract solenoid

- press advance solenoid

- pneumatic solenoid to clamp material

Procedure:

1. Make the electrical connections between the PLC and the press station.

2. Enter the Ladder logic, and test the module by itself.

3. Integrate the components with the other parts of the system and produce parts.

Submission:

1. Pre-lab and updated laboratory materials.

3.2.4 Part D - Variable Feed Drill

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Objective: a PLC will be used to control a variable feed drill

Pre-Lab:

1. Examine the other components in the lab and determine what is required for proper operation of the drill.

2. Design the controls for the drill.

3. Develop the ladder logic required for operation

Process Description:

The drill press will detect when the material is in place for drilling when a hole is detected by an optical sensor mounted. When sensed it will set a bit true in memory (B3:0/02) that will cause the material feeder to stop. A pneumatic cylinder will be actuated to clamp the strip. At this point drilling will begin. When the drill is done the pneumatic solenoid is released and the material feeder allowed to continue.

The drill will be controlled using an analog output card for feed velocity, and using digital inputs to measure position. For moving down (drilling) the analog output should be +2V, -10V is used for retracting, and 0V is used for no motion. The ladder logic below will make the analog output card drive the drill to advance when a bit is set, and retract when a second bit is set, otherwise the drill will be idle.

PLC Inputs:

A DC Input card to accept 12Vdc.

- hole detected sensor

An AC Input card to accept 120Vac.

- drill retracted limit switch

- drill advanced limit switch

- control power on (master power for the station)

- auto mode selected (must be on for plc operation)

PLC Outputs:

An AC Output card to output 12Vdc.

- pneumatic solenoid to clamp material

- drill motor start relay

An Analog Output card will be placed in slot 3 to output -10 to +10Vdc and control drill velocity.

- drill velocity voltage

Procedure:

1. Make the electrical connections between the PLC and the drill station.

2. Set up the I/O modules. You will need to make sure the analog output card is also set up. When setting it up use the ‘autoset’ values option. This will pick memory locations for the card to use - take note of these. (You will need to do this again when all of the programs are combined.) The use the ‘insert ladder rungs’ program to put the functions you need in the ladder diagram.

3. Enter the rest of the ladder logic, and test the module by itself.

3. Integrate the components with the other parts of the system and produce parts.